Spinal instability has been implicated as a cause of low back pain, and it can usually be assessed by studying motion. Kinematic analyses of the spine have been recognized as an effective method for functional examination of the spine and its disorders helping to understand in-vivo 3D spinal mechanics. Imaging modalities such as Computed Tomography (CT) and MRI are suitable to obtain vertebral geometry. However, radiation is a clinical concern associated with CT and while MRI is noninvasive, detection of bone edges especially at endplates and processes where soft tissues attach, is usually difficult. For both methods, the range of motion possible is commonly restricted to motion along or about the longitudinal axis of the body, making it ideal for torso rotation, as these methods constrain the body within the bore of the CT or MRI scanner. An added advantage of both imaging modalities is that they are able to capture images of large bones and organs that in the case of bony structures can be assumed to behave as rigid bodies, which is required to study kinematics. However, bone exterior contours are not always necessary for kinematics analysis of the segments of the body such as the spine, hip, knee, ankle, foot, hand, wrist and shoulder as long as the image shows consistent landmarks between imaging positions.
What is needed in the art is a non-invasive, reliable and robust method for kinematic analysis of segments of the body using an MRI-based bone-marrow model.